Sewing machines



Jan. 13, 1959 w z 2,868,149

. I ,SEWING MACHINES Filed July 30, 1956 v 2 Sheets-Sheet l Filed July 30, 1956 2 Sheets-Sheet 2 I machine; with' 'thecutter" bar disengaged;

2,868,149 .1. SEWING -MACHINES Karl Winz, Kaiserslantem, Hall, Gerniany, assignor to I G. M.Pfali A;-G.,"'.Kaiserslautern,.Pfalz, Germany, a

joinfistock company Application July:30, 1956 ,iS erialNo. 600,748 Claims priority, application GermanyAugust 9;1955 Z EIaims. cram-125) ;This invention relates to 's'ewingmachines. having a cutting ,arrangement L for trimming .or .separating the stitched materials alongside the row of stitching.

I It is one objebtdfithe-present invention to provide a means whereby the engagement and disengagement of the cutting means mayhbe. effected whilst. stitching is.in

, progress and without the operator having to use the hands" for such purpose.

This is in contrast tol known arrangements whereQfOr example,- two manipulations of a control member iare required to be made by anoperator one for engagement a given non-operative. positionl'to befdiseng'agd.

Iln accordancewithithej present inv'ention'the object is achieved'by using a'isinglecon'trol lever both for engage ment and disengagement "of :the'cutt'er; i'andacting always "in' the'same directio-n,"said'controllever acting inthe one '.ca"se on thecutter bar to'r'no've it into operative position and at the same time .to" hold a pivoted disengagement l .leverl'inoperative,l'andacting' in" the" otherTcase on'said .pivo-ted lever to effect" a release' of' 'theicutter bar.

A machine" or. the" 'type" in which. the improved mechanis'nr'in accordance"withthefpreseiit invention can be incorporated-to advantageisdisclosed in U. S. PatentNo. 2,538,271to GJ'M. "R'eimeri et a1.

Further features of: the invention and details Iof "the advantages obtained; thereby are"apparent" from"the following description of one" embodiment;i'illustratd'in the I accompanying drawings, wherein:

removed;

U ted States Paten l Patented Jan. 13, 1959 Slidably-arrangedin:the-head-G is the cutter bar-(.13 which carries: at itsv lower end the cutter blade 14. :The

flatter" co-operates-dnknown manner with.-a.stationary lowerscuttenb'lade .(notshown) mounted inkthe stitch plate. .Whens the cutter is.inpperation, .it reciprocates vertically tov efiec't a: trimming or.-severingi operatiomon .the .fabricalongside theline-of. stitching. This-:is well known in the art. The. return spring 16, which-is connec ted at one. end to the 11001017 of-the cutter bar 13 stantiallyt-vertical :path.

and attheother: end toithe hook 18. fixed in th61h6ad"6,

draws the-cutter bar 13 upwards into theposition shown in Figs.-1.andZ-whenthe-cutter .drive is disconnected. The cutter drive. is. effected. in .known manner. from an eccentriotnotnshown) arranged on the arm shaft, an eccentric rod-19 .andardrivelever; 20 which is' adjustab ly 'linked'thereto. .This .-lever-.. 20 is secured'to-the cutter -drive.shaftfizz-amounted. in lugs 21 'of the head 6, such shaft havingclamped .to. ..-it-the cutter drive crank 23.

.To thecutter-"drive.,crank. 23 is securedthe'sleeve-or bushing 24.which receives aslidable pin. 25 the inner end of which may engage the notch or recess 26 in the edge of the-cutter bar 13. ,.The pin 25,-the outer end'of: which tspringfnot shownwhichpresses it continuously against the front edge .28 ofthecutter-bar .13, and therefore {tends to place it in the,.notch. or.recess .26.

The sleeve.24..with.the .pin 25 projects freely througha slot 29. in :thezhead plate 30 (Fig. .2 which is secured to thehead of. the machine by. means ofscrews 31. .As the .said..armvshaft-rotates,:the crank.23 oscillates and thereforev moves. .the-,pin..25. up. and down ina short, sub

.lnfltheadisen gaged ,positionof the cutter .theecutterul i..the.cutter.bar 13;:is presseddownwardly againstv theaction. of. thespring, 16. until the pin 25 slides intotthe.recesslinthe.cutter bar..13 oscillating move- .ments..of=thezdrivingcrank23 are then. transmitted to-the .cutterihar -13..as verticaL reciprocations. -The extent. of t-he..movement.; of the. cutter bar 13. can be fixed: by ad- .justing. the.eccentric rod-19 onthe driving lever .20.

. Disengagement ofthe, :cutter 14- is :etlected:by:extractring. the pin:.25, from. the. recess-26. .of the. cutter. barv 13, by -meansof the. nut 27, wherebythe cutter.bar.13 returns to' itsinitialraised position under the actionof the -return.spring.16f(Figs..1 and..2). v

.Accordingto.tl1is.invention,..instead of the. usual .pressureplate for ..the cutter .bar, there isarranged at the .upperend .ofthe.cutter..bar.:13, apressure member. .32

Fig. lis' a per'spective'vrew. of a"sewmgfmachine"taken from the" rear. "'such" machine "having the invention incorporated 'in'it. "'The' cover plate for the head 'is Fig. 2 is'affrontperspective 'view 'of a""partiof the Fig." 3" is a View similar'to Fig. 2',"but with the cutter bar engagedand"with 'the a'rm'in the'engag edposition;

T'Fig: 4' shows the armin' there'sting" position; -and" Fig. 5 "shows the" arm" inthe position at theibeginning .of disengagement.

The sewing machine consistingbf'base plat'3; support 4, armS and head 6=:is" mounted "in'cutout portion '1 "of ."table top 2. The reciprocating needle bar"8 is"arranged in'the head6' which carries'the needle 7far'1d'is driven in ""the' usual manner'bywayf of" a crank"operated by the arm "sha'ft' WhlChlS" notshown 'in thedrawing. The pre'ssei' bar 10'carrying the presser foot 9 may 'be' raised "as desi'red either 'by"the"1ifting lever 1 1acted upon by lrneefilever or treadle;""or by"thfinger lever 12. v v

:10] the head=p1ate=30 (Figs. :1 and '4.) rby r-means of ".the

. (Eig..;2)- which .issccured .tothe. cutter ,bar.13. by ascrew .33. In at borer34oi the pressure member 32 is displace- -ably. mounted .a slidable. bolt -35 having. a flange. 36: at .its one .end againstwhich one endaspring .37 reacts, this .spring being .wound around the bolt 35. The other end of :suchspring is :biased .against .the- .adjacent end of the pressure member 32.

Apin 3sextending'upwardly; from the bolt. 35 is guided vin .a.slot.-39 .inthe-top of the..pressure member--32. The

spring 37. presses thebolt. 35 'to the right (Figs. .2,-.5)

until .such. pin..38 strikes against the closed: enclof .the

slot 39 at thatrend o-fmemberfal.

A carrier or' bracket-40,.. having two arms 4l'between which atriplever 421s mounted on screw'43, is secured screws 31 'which :hbldthewhead :plate inposition. The

ltrip lever '42? hasra2downwardly extending bifurcated arm 44 which embraces the sleeve'24 and has an upwardly extending arm "45,:shaped at the top toprovide a stop -member 46. The trip lever 42 is under "the irifl-uence'oi 14 (Figs. 1- and 2) the inner-end of pin..25.rnerelyislidesup and .down 0n-.:to..the-.edge..28..of.the-low.er partofthe'cutter .-.bar..13,.below the. notch. or recess\26. If, for engaging I the pin 38 (Fig. 2) in the raised position.

a U-shaped spring 47 which is-p'rovided with coils in both arms. This spring is suspended from a slot 48 in the arm 45 so that its arms hang down one on each side of that arm and their lower extremities enter into blind "holes 48 in the arms 41 of the said carrier 40.

Y The spring 47 tends to keep the trip lever 42 in position of rest shown in Fig. 4, namely'with the forked end 44 disposed in the immediate vicinity of the nut 27 of the pin 25, but without actuating the latter. During the up' and down movement of the cutter bar 13, the sleeve 24 does not leave the fork 44.

On the rear end of the arm of the sewing machine there is mounted on a bolt 49, jointly with the lifting lever 11, a double-armed control lever 50 (Fig. l) the rear arm 51 of which is pivotally connected to a pressure rod'52 constrained by a pressure-spring 53. The pressure rod 52 passes through a 'bore 54 in the base plate 3 Y of the machine, and under the table top 2 where, through aTeversing lever 55, it is connected to an actuating rod 56 which is moved in turn by a control member such as a knee lever, pedal, magnet or the like (not shown).

I The front arm 57 of the control lever 50 is bent so that its 'end portion 58, extending horizontally parallel to the upper edge of the head plate 30, is disposed just above the pressure member 32 when the cutter bar is disengaged. An angle memberp60', the free end of which is approximately parallel with the said portion 58, is secured to such portion by means of screws 59.

In Figs. 1 and 2 the cutter bar 13 is raised, being in the disengaged position. The pressure bolt 35 extends out of the pressure member 32 at its head end under the pressure of the spring 37 and the pin 38 is disposed against the closed end of the slot 39. The upper arm 45 of the trip lever 42 is disposed at the front of the bolt 35 under the action of the spring 47 and the forward end 58 of the control lever 50 is on the right side of To engage the cutter the control member is actuated topull down the rod 56, thereby moving the control lever 50 clockwise (Fig. 1) and therefore counterclockwise in Figs. 25. At the same time the cutter bar 13 is-moved downwardly by the overhanging portion 58,

against the action of the spring 16, and simultaneously, because of the circular movement of part 58 about the pivot bolt 49, the pin 38 is moved to the left (Fig. 2) together with the bolt 35. This bolt 35, abutting the edge 46 of arm 45 of the trip lever 42, moves such lever counterclockwise against the action of the spring 47, until the descending angle member 60 on the said portion 58 of the control lever 50, instead of striking against the edge 46 of .the arm 45 passes said arm 45 (Fig. 3). When eventually the arm 45 of the trip lever 42 slides from the front of the descending pressure bolt 35 it is urged by spring 47 on to the outer face of angle member 60 and is now retained thereby. The cutter bar 13 having been pressed down by the end 58 sufficiently for the pin 25 on the cutter drive crank 23 to engage the recess or notch 26 of the cutter bar 13, the cutter 'bar is now If the cutter 14 is to be disengaged, the control memher is actuated again to pull down rod 56 and, in the same manner as before, owing to the ensuing swinging of the control lever 50 counterclockwise (Fig. 5), the

angle member 60 now strikes against the stop member 46 of the arm 45, since the latter can no longer be kept out of'the path of movement of the angle member 60 by the pressure bolt 35. As a result, the trip lever 42 is swung clockwise (Fig. 5). At the same time the forked end 44 of the trip lever 42 engages the nut 27 and pulls the pin 25 out of recess 26 in the cutter bar 13 (Fig. 5) which then, as described above, returns to its initial position under the influence of spring 16. Upon the release of the control member, the front end 58 of the control lever 50 and the trip lever 42 return to the position shown in Fig. 2.

The device has been explained with reference to the example of an edge cutter or trimmer. It may also be used for the engagement and disengagement of cutters for severing material into separate pieces.

What I claim is:

1. In a sewing machine having a work support and a machine arm including a main drive shaft and supporting a machine head vertically above said work support, a reciprocating cutter barmounted in said machine head havinga cutter end extending downwardly and an operating end, .extending upwardly from said machine head and having a recess, a spring extending between said cutter bar and said machine head biasing said cutter bar toward inoperative position away from said work support, driving means including a crank arm and a shaft journaled in the machine arm linking said cutter bar by way of a slidable pin on said crank arm for reciprocating movement to' said main drive shaft, said slidable pin extending through an aperture in the machine head for engaging said recess, an adjusting nut disposed endwise and circumferentially of said slidable pin, a pressure member disposed on the operating end of said cutter bar and having a slot, a spring biased slidable bolt extending through said pressure member and having an outwardly extending conformation movable in said slot, a trip lever extending substantially parallel to said cutter bar and mounted on the machine head having one arm in operating engagement with said adjusting nut and the other arm proximate said pressure bolt, a spring secured to one arm of said lever and biasing said lever toward' said pressure bolt, a double armed control lever mounted on a pivot laterally of the machine including manipulating means and spring biased toward inoperative position, said control lever extending lengthwise of the machine arm and having an upwardly extending portion presenting a transverse member proximate said a reciprocating cutter bar mounted in said machine head having a cutter end extending downwardly and an operating end extending upwardly from said machine head and having a recess, a spring extending between said cutter bar and said machine head biasing said cutter bar toward inoperative position away from said work support,

. driving means including a crank arm and a shaft journaled .inthe machine arm linking said cutter bar by way of a slidable pin/on said crank arm for reciprocating movement to said main drive shaft, said slidable pin extending through an aperture in the machine head for engaging said recess, an adjusting nut disposed endwise and circumferentially of said slidable pin, a pressure member disposed onthe operating end of said cutter bar and having a slot, a spring biased slidable bolt extending through said pressure member and having an outwardly extending conformation movable in said slot, a trip lever extending substantially parallel to said cutter bar and mounted on the machine head having one arm in operating engagement'with said adjusting nut and the other arm proximate said pressure bolt, a spring secured to one arm of said lever and biasing said lever toward said pressure bolt, a double armed control lever mounted on a pivot laterally of the machine including manipulating means and spring biased toward inoperative position, said control lever extending lengthwise, of the machine arm and having an upwardly extending portion presenting a transverse member proximate said pressure member transversely of said slidable bolt arcuately movable about said pivot into engagement with said pressure member and said conformation to move said other arm outwardly, said one arm inwardly, and said cutter bar downwardly when said cutter bar is idle, and an angular abutment member on said transverse member adapted when said References Cited in the file of this patent UNITED STATES PATENTS 1,426,466 De Voe Aug. 22, 1922 1,932,953 Card Oct. 31, 1933 2,308,470 Parry Jan. 12, 1943 

